千斤拔属药用植物DNA条形码鉴定研究

Identification of DNA barcoding on medicinal plants in Flemingia Roxb. ex Ait. et Ait. f.

目的筛选一种可准确、高效鉴别千斤拔属Flemingia Roxb.ex Ait.et Ait.f.药用植物的DNA条形码序列。方法对4种14份千斤拔属药用植物的ITS2、rbc L、psb A-trn H序列进行扩增和测序,同时查找NCBI数据库中千斤拔属植物的相应序列,共计7种20份,比较不同序列的扩增效率及测序成功率,并对其进行种内、种间变异分析,barcoding gap检验及NJ聚类图分析,以评估不同序列对千斤拔属植物的物种鉴别能力。结果测序成功率方面,ITS2与rbc L序列对所分析样品的测序成功率为100%,psb A-trn H的测序成功率为85.71%;3条序列中,只有ITS2在barcoding gap检验中具有显著gap;从NJ聚类图来看,ITS2可明显区分千斤拔属植物的不同物种(除F.philippinensis与F.stricta外)。结论 ITS2序列能准确鉴别千斤拔属药用植物,可作为千斤拔药材基原植物鉴定的条形码序列。

Objective To screen a DNA barcoding sequence that can identify the medicinal plants of Flemingia Roxb. ex Ait. et Ait. f. accurately and efficiently. Methods Four species and 14 individuals of Flemingia Roxb. ex Ait. et Ait. f. were collected, the（second internal transcribed spacer, ITS2） of ribosomal DNA, rbc L, psb A-trn H of chloroplast DNA were amplified and sequenced. Meanwhile, the NCBI data were retrieved and the according sequence was downloaded. The total numbers of species and individuals were six and twenty. The PCR amplification and sequencing efficiency, barcoding gap, and NJ trees were used to evaluate the efficiency of species identification. Results The sequencing success rates of ITS2, rbc L, and psb A-trn H were 100%, 100%, and 85.71%, respectively; Among the three DNA barcoding sequences, only ITS2 has remarkable barcoding gap; ITS2 could distinguish every species of Flemingia Roxb. ex Ait. et Ait. f.（except F. philippinensis and F. stricta）. Conclusion ITS2 could identify the medicinal plants of Flemingia Roxb. ex Ait. et Ait. f. accurately and efficiently, and could be used as an ideal DNA barcoding of species identification for medicinal materials of Flemingia Roxb. ex Ait. et Ait. f.